engineer’s estimate · traffic engineering design division traffic control devices design manual...

ENGINEER’S ESTIMATE

MARYLAND STATE HIGHWAY ADMINISTRATION

Office of Traffic and Safety Traffic Engineering Design Division

Traffic Control Devices Design Manual

July 2017 1

ENGINEERS ESTIMATE

The Engineer’s Estimate is an important part of the overall design process. It is a determination of the construction costs for any given project. The estimate is then used for programming and funding proposes. Preparing the estimate requires knowledge of construction methods, fabrication processes and construction costs based on the measurement and payment section in the Specifications. An Engineer’s Estimate is required for all projects.

Every item that is called out on the plans shall be included in the estimate. There are also items not specifically called out on the plans that need to be included in the estimate. Each item must be paid for in some manner. It shall include the category code number (for Inserts), item number (for Areawides), item description, unit of measure, quantity, unit cost and total cost for each item. The total cost for each item is then summarized to receive the overall engineer’s estimate. For signal, signing, pavement marking, and lighting designs, the estimate may include two types of construction items.

• First are items that are furnished by MSHA and installed by the contractor.

• Second are items that are furnished and installed, removed or only installed by the contractor.

Examples given in this section refer to equipment being “Furnished and/or Installed by the Contractor” unless otherwise indicated. It’s important to note that the classifications mentioned above and as described throughout this chapter are only pertinent for Areawide and Insert Projects. While an Engineer’s Estimates and the items described within this section are still necessary for Developer and Design-Build Projects, MSHA will not furnish any material unless stated in the RFP, thus all material and equipment

costs are the responsibility of the Contractor/Builder.

The Engineer should be aware of the Engineering Change Notice (ECN) process and the content of a Specification. Knowing the ECN process and the hierarchy of Specifications will centralize the Engineer’s understanding of how changes in directives, guidelines, standards, specifications, or engineering practices may affect his or her estimate and bid packages.

ESTIMATING QUANTITIES

The first step in producing an estimate is to calculate the quantities that will be required for the project. Quantities are calculated using the design as shown on the plan sheets. Quantities are measured in various ways. The most common units of measure are cubic yards, linear feet, each, lump sum or square feet. Each quantity shall have a unit of measure. This defines how the item is paid; refer to the latest approved version of the MSHA’s Standard Specifications for Construction and Materials. The specifications and special provisions define how an item is paid for (unit of measurement) and what the payment does and does not include.

In the material following, various examples of items needed for signing, pavement marking, signals, and lighting are discussed.

Signs Signs are paid for by the square foot (SF) area of the sign face, including all necessary mounting hardware for ground mounted and overhead signs. This is the same for both sheet and extruded aluminum, however they are paid for as separate items. This is due to the different associated costs. Sign overlays are always constructed from sheet aluminum.

Signs are typically furnished by MSHA and installed by the contractor for all signal related




July 2017 2

signs under most Areawide Contracts. It is important to clarify in the early design stages whom will be supplying the signs for a given project.

Available Items Unit

Sheet Aluminum Signs Square Feet

Extruded Aluminum Signs Square Feet

Overlay Overhead Signs Square Feet

Overlay Ground Mounted Signs Square Feet

Ground Mounted Sign Supports Wood and Steel Ground Mounted Supports are paid for by the linear footage of installed support. Where breakaway steel posts are required, there will be one breakaway base support system for each post. For wood supports, the additional modifications for breakaway are incidental and not measured or paid for. Concrete foundations for steel supports are paid for separately based on the sizes listed in the Book of Standards.

The calculation of support length requires the collection of roadside cross sections, as discussed in the Field Review section of the Signing chapter. As an example, we will look at the following sign:

The ground mounted support length can be calculated in four sections, numbered 1 to 4 in the picture above. The support length for each of these sections is determined as follows:

SECTION I: This section equals the sign height. New supports should extend to the top of the sign.

SECTION II: This section is equal to the MdMUTCD mounting height, 5’-0” minimum for rural areas and 7’-0” minimum in urban areas. This section will usually be 7’-6” for breakaway steel supports. Note that these dimensions are measured at a minimum from the top of curb or near edge of traveled way as specified in the MdMUTCD.

SECTION III: This section is the additional support length due to the roadside slope. It can be calculated as the overall embankment height (5.00 feet in the above example) times the ratio of support offset to slope length. For the sign shown above, this calculation for the right support would be as follows:

Support offset from top of slope (near edge of traveled way) = 6’ + (10’)1/5 = 6 + 2 = 8’-0”Section = (5.00) 8/20 = 2.00 Feet

SECTION IV: This section is the depth of bury below the ground line for the support. For steel supports, this number is zero (0’-0”). For 4”x4” and 4”x6” wood supports, it is 5’-0” and for 6”x6” and 6”x8” supports it is 6’-0”.

10’-0”

Section I

MdMUTCD Clearance

6’-0”

Elevation 95.00

Elevation 100.00

Section II

Section III

Section IV

5’-0”

4’-0”

Figure EE.1 - Ground Mounted Support Lengths




July 2017 3

The overall height of the right support in the above example (for wood supports) would be 5’ (sign height) + 7’ (mounting height) + 2’ (addition for slope) + 5’ (assuming 4”x6” wood) = 19’-0”.

Another item to be careful of is Aluminum Angles. They are considered incidental hardware and not paid for when used to mount extruded signs to wood supports. However, they are measured and paid for when used to mount a taller sign to existing steel supports. The angles are used to connect the new panels and provide stiffness that would have come from the supports. They are usually installed in pairs of two, with each angle being twice the height of the sign addition/extension (See “Extruded Aluminum Details and Vertical Support Attachment” in MSHA’s Book of Standards for Highways and Incidental Structures). The maximum height that a sign can be extended with aluminum angles may require input from the TEDD structures team during the review process.

Overhead Structures Overhead Supports, both cantilever and overhead structures, are paid for by each structure installed. This number includes anchor bolts, sign supports, and all hardware. Foundations are paid for separately based on the size specified by the plans.

Sign Lighting Sign lighting requires quantities for luminaires, 1” rigid steel conduit, 1” flexible steel conduit, electrical cable, and ground wire. If the sign structure is new, the I-beam supports for the luminaires are incidental to the structure. If the sign lighting is being installed on an existing sign structure or being relocated, they will have to be quantified. The number of luminaires is determined from the Sign Lighting Tables in Appendix A-6 of this manual. The remaining quantities can be calculated as follows:

Flexible Steel Conduit = (3 LF) * (# of luminaires)

Rigid Steel Conduit = [(# of luminaires)*(6 LF + distance from bottom of truss to bend in I-beam luminaire support) + (distance from the upright support to the last luminaire along the truss)] + 5% increase to account for bending


Wood Supports (per size) Linear Feet

Steel Supports (per size) Linear Feet

Breakaway Base Support System

(Type A or Type B)

Each

Concrete for Sign Foundation Cubic Yards

Aluminum Angle (2½ x 3½ x ¼) Linear Feet


Cantilever Sign Structure Each

Overhead Sign Structure Each

Concrete for Sign Foundation Cubic Yards

4” PVC Conduit in Sign Foundation

Linear Feet




July 2017 4

Electrical Cable = [4*(distance from bottom of upright support to the bottom truss + the distance along the bottom truss from the upright to the farthest luminaire) + 4*(# of luminaires)*(6 LF + distance from bottom of truss to bend in I-beam luminaire support)] + 10% increase to account for bending and slack

Ground Wire = [(distance from bottom of upright support to the bottom truss + the distance along the bottom truss from the upright to the farthest luminaire) + 2*(# of luminaires)*(6 LF + distance from bottom of truss to bend in I-beam luminaire support)] + 10% increase to account for bending and slack

Miscellaneous Sign Items When needed, sheet aluminum signs are used in conjunction with signals to achieve a desired message. They can be mounted on the mast arms, span wire, banded to the signal pole, or installed as a ground mounted sign. Signs may also be banded to overhead structures and light poles.

(Note: Equipment Furnished by MSHA)

Depending on the type of installation you are designing, there are other miscellaneous quantities that may be necessary.

Sign Removal Items Whenever the contractor must remove existing signs and supports, items must be included in the estimate. In general, sign removal is paid for by square footage (SF), including removal of the supports if specified on the plans. When signs will be removed and relocated, refer to the Special Provision for the appropriate pay items.

Pavement Markings Lane lines, edge lines, channelizing lines and gore markings are paid for by linear footage (LF) of material installed. Arrow, word and symbol markings are paid for by square feet of material installed. When calculating quantities, they should be separated by line width, color, and material (for example 12” White Thermoplastic). The removal of existing pavement markings should be accounted for as a separate line item. All existing pavement markings, being replaced or removed, are paid for in linear feet.

Although snowplowable raised (including recessed) pavement markers (SRPMs) are not specifically called out on the marking plans, a separate line item is needed based on requirements of the MdMUTCD and Book of Standards. For instance, RPMs are paid for by each so the quantity should be doubled when side-by-side markers are needed along elephant tracks for freeway off-ramps.




July 2017 5

* NOTE - see Category Code Book for exact item descriptions to be used on the plans and for other pay items.

Signal Cabinet and Controller The cabinet and controller are items that are furnished by MSHA and installed by the contractor. These items are paid for per each. For new installations, the cabinet, controller and video interface equipment are all combined as one pay item but they can also be provided individually to meet specific project needs. The cabinet also requires a

concrete foundation that is incidental for Areawide projects but paid for as a separate item in Insert projects. A Metered Service Pedestal is used to provide the power supply for new cabinets.

(Note: Equipment Furnished by MSHA)

Signal Structures Signal structures are paid per structure, for each size. For example, “Furnish and Install 27’ Steel Pole with 50’ Mast Arm” is a different item than “Furnish and Install 27’ Steel Pole with 60’ Mast Arm”. Signal Structures also require concrete foundations that are incidental for Areawide projects but paid for as a separate item in Insert projects. These




July 2017 6

items are typically furnished and installed by the contractor. Strain poles require the use of span wire to attach the signals and signs. Span wire is measured per linear foot (LF). This quantity should account for the sag and extra at either end to attach to the strain poles.


Steel Pole with Mast Arm (per size) Each

Strain Pole (per size) Each

Breakaway Pedestal Pole (any size)

Each

Cut, Clean, Galvanize and Cap Signal Structure

Each

Concrete for Signal Foundation Cubic Yards

Steel Span Wire (3/8” or 1/4”) Linear Feet

Class 2 Excavation CY

Audible/Tactile Pedestrian Pushbutton Station & Sign

Each

Signal Heads Signal heads are paid for per section of standard. They are broken out per the size and type.

Detectors Microloop probes are typically paid per each, inclusive of the lead-in cable and three probes. Saw cuts are measured and paid per linear foot. Video detection camera to controller cable is incidental to the item for the camera and is available in any length.


Microloop Triple Probe Set (up to 1000’ Lead-in Cable)

Each

Non Invasive Microloop Triple Probe Set (up to 1000’ Lead-in Cable)

Each

Saw Cut for Signal Linear Feet

Loop Wire Encased in Flexible Tubing (No. 14 AWG)

Linear Feet

Video Detection Camera (including camera to controller cable) Each

Signal Preemption Using an optically activated priority control system requires the inclusion of the detector eye, emitter, a discriminator, card rack and cable. The first four items are paid per each. MSHA will typically install three emitters for use with firehouse preemption. The cable is paid for per linear foot from the detector eye to the cabinet. Account for an extra 20% in the length of cable for slack, coil, connections, etc.

When using a hard wire for preemption, a push button shall be installed in the firehouse.


LED Vehicular Traffic Signal Head Section (12”) Each

LED Vehicular Traffic Signal Head Section with Louvers (12”)

Each

16” LED Countdown Pedestrian Signal Head Section

Each




July 2017 7


Optically Activated Priority Control System Detector Eye Each

Optically Activated Priority Control System Detector Emitter

Each

Optically Activated Priority Control System Discriminator

Each

Optically Activated Priority Control System Card Rack

Each

Push Button for Preemption Each

Optically Activated Priority Control System Detector Cable (4 conductor No. 20 AWG (7x8) stranded cable)

Linear Feet

Signal Removal Items Remove and Dispose of Foundation 12” Below Grade is only used with Areawide projects.


Remove and Dispose of Existing Signal Equipment

Lump Sum

Remove and Dispose of Foundation 12” Below Grade

Each

Pedestrian Facilities ADA ramps and sidewalk are measured by square feet of concrete sidewalk. Other items associated with ramps are detectable warning surfaces, curb and combination curb and gutter. Backer curb is paid for by linear feet of curb and the quantity can be increased if the height of the backer curb is higher, such as 16” in certain areas.


Type A Curb Any Height or Depth LF

Type A Combination Curb and Gutter Any Height and Depth

LF

5 Inch Concrete Sidewalk SF

Detectable Warning Surface SF

Placing Furnished Topsoil 4 Inch SY

Turfgrass Sod Establishment SY

Traffic Barrier Where required to protect roadside hazards, such as at sign structures and light poles, traffic barrier quantities must be included. There are separate items for the barrier and each type of end treatment.

Wiring When estimating cable, use total measured quantity plus 10-20% to account for the excess in handholes, cable slack,


W-Beam Traffic Barrier Linear Feet

Traffic Barrier End Treatment Each

Trail End Anchorage Each

Surface Adjustment for End Treatments Cubic Yard

W Beam Barrier Reflective Delineators Each

Remove Steel Post and Foundation

Each

Remove Existing Traffic Barrier Linear Feet

Remove Existing End Treatment Each




July 2017 8

connections, splices (loop wire to lead-in and ground mounted HIBs only), and drip loops. Remember to include the pole height and underground conduit bend depth in the measurements when a pole is used to transport the cable from overhead to underground. For loop wire, include the number of turns per sawcut, plus two times the distance from the detector to the handhole as well as an additional 5% to account for twisted cable.


Signal Wiring

Electrical Cable, No. 14 AWG (per number of conductors) LF

Electrical Cable, 1 Conductor 250 kcmil, No. 4 or No. 8 AWG LF

Electrical Cable, 2 Conductor No. 14 AWG, Aluminum Shielded LF

Stranded Bare Copper Ground Wire (No. 4 or 6 AWG) LF

12 Pair Communication Cable, Jellyfilled (Underground) LF

12 Pair Communication Cable, Self-Supporting (Overhead) LF

Electrical Cable, 3 Conductor No. 12 AWG Tray Cable LF

Disconnect, Pull-Back and Reroute Cables LF

Lighting Wiring

Duct Cable (per # conductors and gauge size) LF

Electrical Cable (per # conductors and gauge size) LF

Stranded Bare Copper Ground Wire (per gauge size) LF

Solid Ground Wire (per gauge size) LF




July 2017 9

Conduit Conduit is paid for per linear foot (LF) and should be calculated by measuring the length plus some extra to account for grading and going around obstacles. Typically, in Areawide projects conduit is measured as “up to 4 inch,” rather than measured by the linear foot, per specified size.


Schedule 80 Rigid PVC Conduit – Trenched (per size) Linear Feet

Schedule 80 Rigid PVC Conduit – Slotted (per size)

Linear Feet

Schedule 80 Rigid PVC Conduit – Bored (per size)

Linear Feet

1” Electrical Conduit, Galvanized Sleeve

Linear Feet

1” Liquid Tight Flexible Non-Metallic Conduit for Detector Sleeve (per size)

Linear Feet

1” Rigid Steel Conduit Linear Feet

1” Flexible Steel Conduit Linear Feet

Galvanized Steel Conduit (per size)

Linear Feet

EMT Conduit (per size) Linear Feet

Light Structures Highway lighting has several types of structures. The structures include the pole and bracket arm. The transformer bases and concrete foundations are paid for separately.


Concrete for Light Foundation Cubic Yard

High Mast Light Structure (per pole height)

Each

Light Structure and Bracket Arm (per pole height and arm length)

Each

Aluminum Light Structure and Bracket Arm (per pole height and arm length)

Each

Breakaway Base Support Each

Lighting arm on Signal Structure (per arm length)

Each

Lamps and Luminaires Highway and sign lighting has several types of luminaries and lamps. They are paid for together based on the style, type and wattage.


LED Roadway Luminaire Each

High Mast Lighting Assembly (including lowering device) Each

LED Sign Luminaire Each

Other Electrical Equipment In addition to the wiring and conduit there is other electrical equipment that shall be defined. Connector kits for lighting are quantified as per each item, except at intersections. Handholes are commonly used with signals and electrical manholes with lighting design. Ground rods are usually incidental in Areawide projects but paid per each in Insert projects. With any electrical design there will also be a Pole or Base




July 2017 10

Mounted Cabinet and associated equipment dependent on the power service. Refer to MSHA’s Standard Specifications for Construction and Materials for appropriate equipment.


Electrical Handhole Each

Ground Rod Each

Electrical Manhole Each

Connector Kit, Type I Each

Connector Kit, Type II Each

Connector Kit, Type III Each

Connector Kit, Type IV Each

Base Mounted Lighting Cabinet (277/480 V, 3 Phase, 4 Wire) Each

Base Mounted Lighting Cabinet (120/240 V, 1 Phase, 3 Wire)

Each

Pole Mounted Lighting Cabinet Each

Embedded Service Pedestal Each

Miscellaneous Test pits are used to verify there are no underground utility conflicts with the proposed equipment. For signals and light structures, use one cubic yard for the cabinet and one cubic yard for every two pole foundations.

Maintenance of Traffic is paid per each for Areawide Contracts and is based on the total estimate amount (typically 1-3 EA). Otherwise, it is paid as Lump Sum based on items specified in the Standard Specifications for Construction and Materials Book.


Test Pit Excavation Cubic Yards

Maintenance of Traffic Each

PRODUCING THE ESTIMATE

Once the final quantities have been determined, the steps required to produce a final estimate vary depending on the type of project. This is due to the different contracting procedures and construction forces available. The primary difference between the different estimate types lies in how the unit prices are determined. In the case of Shop Forces and Areawide projects, all unit prices have been established ahead of time. For Insert and advertised projects, the unit prices must be estimated based on similar projects.

Who Pays for What Payment provisions for every item in a contract are defined by the Standard Specifications and the Special Provisions. These will tell you what items are paid for, how those items are measured, and what items are incidental to that payment. For each quantity, determine who will supply the appropriate materials to complete the work. This will be determined by current MSHA practice and also by the contract type. For example, Signs are MSHA supplied on Areawide contracts and can be Contractor supplied on Insert or Advertised jobs. As mentioned earlier, an estimate should include a separate section tabulating the quantities for all MSHA and contractor supplied equipment and materials (this is referred to as the “Equipment List” with sections “A” and “B” respectively).

Shop Forces/Areawide Projects The unit prices used for Shop Forces and Areawide estimates are usually determined




July 2017 11

before design of the project has begun based on the awarded bid prices for the Contract. In some instances, a project will require an item for which there is no unit price, and the designer must make a reasonable estimate. These items will then have to be either negotiated with the contractor or purchased and installed separately by MSHA.

On the other hand, if a project requires an item for which there is no unit price, review the existing items and determine if it makes sense to use another item in its place. For instance, if a 38 foot mast arm is required but doesn’t exist in the contract, the designer could call for a 50 foot mast arm (that does have a unit price) and cut the arm to 38 feet.

Due to the diverse nature of Areawide construction, certain items have been customized for this contract and are paid for differently than on other projects. For instance, signal poles, ground rods and

concrete foundations are usually paid for separately, however, for the Areawide contract they are paid for as a single, all-inclusive, item for signal poles. It is important to become familiar with the Special Provisions for a contract, where these differences are explained for each contract. An example of an Areawide estimate is shown below.

Advertised and Insert Projects Unit prices for Advertised and Insert projects are calculated from the Price Index using similar projects bid over the previous 12 months. These prices are compiled in a database and made accessible in the MSHA “Estimator Program”. They are applied to the quantities developed in the previous section to estimate the total project cost. On these projects the contractor usually furnishes all materials and equipment. However, MSHA still typically furnishes signs, signal cabinets and associated equipment. An example of an Advertised/Insert estimate is shown below.




July 2017 12

Figure EE.2 - Typical Areawide Estimate




July 2017 13

Figure EE.3 - Typical Advertised/Insert Estimate




July 2017 14

WRITE-IN ITEMS

A Write-in item is an item identified in the preliminary design of an Advertised contract that does not have an associated category code number. This item may not have been used by MSHA in the past or is very different from what has been used. In these circumstances a Write-in item will be requested and given a category code number of 800000. Accordingly, a Special Provision to the Standard Specifications for Construction and Materials will be developed for that particular contract.

NEGOTIATED ITEMS

A negotiated item is an item specified in the project design that does not exist in an Areawide contract’s bid items list. Hence, there is no associated bid price for such items and a unit price must be agreed upon between the State and the Areawide Contractor. Similarly, if there is a need for a new item during construction of an insert project, the item will be added as a redline revision and a unit price must be agreed upon between the State and the General Contractor.

Under existing Areawide contracts the need for negotiable items shall be determined during preliminary design. The project schedule will be adjusted if necessary, and research for negotiable item vendors, model numbers, costs, etc. shall begin.

At this point a cost estimate to furnish and install the item will be produced. This should include the cost of the items plus a 20% markup and 6% tax. The man-hours and $ rate plus 65% to install shall be included in the estimated price. The equipment hours and $ rate plus 20% shall also be included in the estimate to install the item. Wage rates are provided in the IFB, and the Equipment rates are from the Rental Rate Blue Book.

When negotiable items and cost estimates have been recognized, a prepared memo for the negotiable item to be negotiated shall be submitted to MSHA’s Traffic Operations Division (TOD). This memo shall include a detailed description of the item, and provide specifications, typicals for the work to be completed, and any other pertinent information such as vendors, phone numbers, addresses, etc.

Following this, TOD will contact the Contractor and request a price based on the information provided. The response is to be requested within 3 weeks. The Contractor shall submit a price including a detailed breakdown of cost, labor, tax and profit to complete the work.

If the Contractor’s cost is within 10% of the engineers estimated cost, the item shall be approved. If the Contractors cost is more than 10% of the engineers estimate, TEDD shall reevaluate their estimate to determine where the discrepancies are and make the appropriate adjustments as needed.

At this time the Design Engineer shall re-evaluate the PS&E schedule and adjust as necessary with approval from the PM. TEDD and TOD will then agree on the price and/or re-negotiate. Once the price has been agreed upon, TOD will set up the item for the remainder of the Contract. TEDD will then PS&E the project to CFD. Note: No project should go to PS&E without approved negotiable items.

engineer’s estimate · traffic engineering design division traffic control devices design manual...

Documents